Aleppo, Syria’s largest city, is in the grip of the country’s civil war. Government attack helicopters and fighter jets circle the city’s skies as rebel factions entrench themselves in Aleppo’s old town and sections of the city’s suburbs. The regime of Syrian President Bashar Assad has dispatched armored columns to flush out insurgents, not unlike its recent crackdown on rebel fighters in pockets of the capital Damascus. One rebel commander in Aleppo told the U.K.’s Daily Telegraph that the fight for Syria’s commercial capital, a city of 2.5 million people, would last months. Rebels are stockpiling medical supplies and munitions, while the U.S. State Department warned of a potential massacre. A pro-government newspaper promised the “mother of all battles.”

Until recently, Aleppo was not one of the major theaters of the Syrian conflict. But it is no stranger to war. With a history as ancient as Damascus — considered to be one of the longest continuously inhabited cities in the world — Aleppo has been won and lost by a succession of empires, sacked by myriad invaders and reduced to rubble by epic earthquakes. That it still stands, and is, indeed, with its thousands of old limestone houses and winding old streets, a UNESCO World Heritage Centre, is testament to the richness of its past and the resilience of its people.

From its early origins, Aleppo was a place where people grew wealthy. Cuneiform tablets from roughly four thousand years ago tell of a settlement called ‘Halabu’ — eventually Aleppo — that was even then a center for the manufacture of garments and cloth. Located not far from the Mediterranean Sea on one side and the river valley of the mighty Tigris and Euphrates on the other, the city found itself in the middle of ancient Egyptian and Hittite trade routes. The Seleucids, a Greek dynasty descended from one of the lieutenants of Alexander the Great, developed the area further, while certain colonnaded avenues and courtyard homes in Aleppo today bear the tell-tale signs of Roman craftsmanship and Hellenistic urban planning.

Following the advent of Islam and into the medieval era, Aleppo became a hub of the Silk Road, a giant entrepot pooling in all the riches of China and India for buyers further west, north and south. Aleppo’s many caravanserais and bath houses bubbled with the chatter of different tongues; by the 16th century, numerous European merchant houses had set up shop to try to get a piece of the action. When one of the witches in Shakespeare’s Macbeth speaks of a sailor’s wife — “Her husband’s to Aleppo gone, master o’ th’ Tiger” — the English audience at the time would have been aware of that faraway city’s allure and majesty.

Aleppo’s many-layered past and cosmopolitan identity is chiseled into its very architecture. The city’s Great Mosque and Citadel — a towering edifice on a hilltop at the heart of Aleppo — were statements of medieval Turco-Arab might erected atop earlier Roman and Byzantine structures. Well into the 20th century, the city remained home to a diverse mix of faiths and denominations. It always had a prominent, flourishing Jewish community — which, for some six centuries, zealously guarded one of the most famous and venerated copies of the Hebrew Bible, now known as the Aleppo Codex. In the city’s outskirts, sits the Church of St. Simeon, a 5th century Byzantine ruin built around the supposed site where Simeon, an ascetic Christian saint, perched himself atop a pillar for 37 years, choosing, as the 18th century British historian Edward Gibbon put it, “the celestial life.”

But while Aleppo’s history was so indelibly shaped by this intermingling of cultures, it was a hardly a bastion of peace. The city was on the frontlines of the Crusades, ever threatened by Frankish crusader mini-states further to the west. In 1119, an army comprising Aleppans, Kurds and Arab tribesmen annihilated a whole Crusader force in a battle remembered by Latin chroniclers as Ager Sanguinis — “field of blood.” The Aleppans’ Turkic commander, though, didn’t consolidate his gains and died later in alcohol-induced indolence. For centuries thereafter, Aleppo was a prize competed over by various warring Turkic and Arab dynasties. In 1400, the Mongol warlord Timur overran the city. One chronicler described the raid “like a razor over hair” and “locusts over a green crop.” Timur, according to accounts, piled high a mountain of thousands of skulls outside the city gates.

Aleppo endured, and would go on to be ruled for nearly four centuries under the suzerainty of the Ottoman empire and later, in the early 20th century, by French imperial mandate. It remained a busy mercantile center. In his famed guidebook to the Middle East, 19th century European traveler Karl Baedeker frowned on the city’s petit bourgeois character: “The Aleppines do not enjoy a very high reputation and the expression ‘the Aleppine is a coxcomb’ is proverbial.”

French colonial administrators attempted to solidify their control and counter nascent Syrian nationalism by playing the territory’s major centers — Aleppo, Damascus and what was then known as the Alawite state — against each other. That legacy of gerrymandering and divisive rule, while a failure, has had a lasting effect: it can be seen in the contemporary politics of Syria and much of the region — the vicious sectarianism, the delicately forged (and oft-cynical) alliances linking interest groups and whole communities to the regime in power. The Assads, who are Alawite, long trusted in the support of Aleppo’s Sunni business elites. With that consensus unraveling, though, what happens in this historic city, a veritable global crossroads, may be a bellweather for the future of Syria and the Middle East as a whole.